Semiconductor device having a chip-size package

ABSTRACT

Disclosed are a semiconductor device, a method for manufacturing the same, and a method for mounting the same. The method for manufacturing a semiconductor device includes the steps of: preparing a package film having a planar configuration whose region is divided into a device-mounting film portion having a device hole forming therein, an external-connection film portion, and a bent portion located between the device-mounting film portion and the external-connection film portion, an external electrode pad being formed on the external-connection film portion on a first surface side of the package film, an inner lead being formed in such a manner as to lead from the device hole to the external electrode pad via the bending portion; mounting a semiconductor chip on the device-mounting film portion on the first surface side by bonding the inner lead to an electrode pad of the semiconductor chip in a region where the device hole is formed; and bending the external-connection film portion at the bending portion 180° toward a second surface side of the package film and fixing the same. The method for mounting a semiconductor device on a mother board in close contact therewith includes the steps of: depositing solder balls on electrode pads of the mother board; and placing the semiconductor device on the mother board and melting the solder balls so as to electrically connect the electrode pads of the mother board and the external electrode pads of the semiconductor device.

This nonprovisional application is a continuation of U.S. applicationSer. No. 10/300,883, filed Nov. 21, 2002 which is a divisional of U.S.application Ser. No. 09/663,616 filed Sep. 18, 2002, now U.S. Pat. No.6,589,817, which is a divisional of 08/944,891 filed Oct. 6, 1997 nowU.S. Pat. No. 6,246,114.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor device having a packagewhich has substantially the same size as that of a semiconductor chipand is particularly suitable for a multiple-output semiconductor chip,as well as a method for manufacturing the same and a method for mountingthe same.

2. Description of the Related Art

Conventionally, packages having substantially the same size assemiconductor chips of this type are called a chip-size package, aμ-BGA, a chip-scale package (CSP), and the like, and various types ofsuch packages have been developed. FIG. 24 is a fragmentary perspectiveview of a semiconductor device having a package of a conventional moldedtype. This semiconductor device is manufactured by forming bumps 242 onelectrode pads of an LSI chip 241, then by resin-encapsulating the LSIchip 241 with a mold resin 243 having substantially the same size asthat of the LSI by using a transfer mold, and finally by depositingsolder balls 244 on external electrodes.

FIG. 25 shows a cross-sectional view of a semiconductor device having aconventional film (film carrier tape) type. This semiconductor device ismanufactured as follows. The surface of an LSI chip 251 is coated withan elastic adhesive (elastomer) 252, a polyimide film 255 on which innerleads 253 and external connection pads 254 have been formed is securedto the surface of the LSI chip 251 by means of the elastic adhesive 252,the inner leads 253 are bonded to the chip electrode pads of the LSIchip 251, and solder balls 256 are deposited on the external connectionpads 254.

In addition, FIG. 26 is a cross-sectional view of a semiconductor devicehaving a package of a conventional flip chip bonding type. Thissemiconductor device is manufactured by forming bumps 262 on the surfaceof an LSI chip 261, then by effecting face-down bonding the LSI chip 261on a substrate 263 formed of a ceramic or an organic material, and thenby encapsulating the chip by using an encapsulating resin 264. Solderballs 265 are deposited on the reverse surface of the substrate 263. Ifthe package of any one of the types shown in FIGS. 24 to 26 is used, itis possible to manufacture a semiconductor device having a package ofsubstantially the same size as that of the LSI.

However, with the semiconductor device shown in FIG. 24, anexclusive-use transfer mold is required, which has been a factorhampering the effort in lowering the cost of the semiconductor devices.

In addition, with the semiconductor device shown in FIG. 25, since aspecial elastic adhesive is used between the LSI chip and the tape, thecontamination of or the damage to the surface of the LSI chip can occur,possibly deteriorating the reliability. In addition, when the LSI chipand the inner leads are connected, a single bonding method in which theleads are bonded one at a time is used. As a result, in multiple-outputpackages, the bonding time becomes prolonged, and has constituted afactor hampering the effort in lowering the cost of the semiconductordevices.

Furthermore, with the semiconductor device shown in FIG. 26, thesubstrate is multilayered in the multiple-output package and isexpensive, and in the case of an LSI chip having a large size, thedifference in the coefficient of thermal expansion between the substrateand the LSI chip in some cases constitutes a problem in the reliability.

SUMMARY OF THE INVENTION

In view of the above-described circumstances, it is an object of thepresent invention to provide a low-cost, highly reliable semiconductordevice suitable for use in a case where a multiple-output LSI chip, aswell as a method for manufacturing the same and a method for mountingthe same, thereby overcoming the above-described drawbacks of theconventional art.

To this end, in accordance with a first aspect of the present invention,there is provided a semiconductor device comprising a package filmincluding: a device-mounting film portion on which a semiconductor chipis mounted; an external-connection film portion arranged on thedevice-mounting film portion and having an external electrode pad formedthereon; a bending portion provided between an end portion of thedevice-mounting film portion and an end portion of theexternal-connection film portion; and an inner lead for electricallyconnecting an electrode pad of the semiconductor chip and the externalelectrode pad via the bending portion.

In accordance with a second aspect of the present invention, there isprovided a semiconductor device comprising a package film including: adevice-mounting film portion on which a semiconductor chip is mountedsuch that the device-mounting film portion faces an obverse surface ofthe semiconductor chip; an external-connection film portion arranged ona reverse surface of the semiconductor chip and having an externalelectrode pad formed thereon; a bending portion provided between an endportion of the device-mounting film portion and an end portion of theexternal-connection film portion; and an inner lead for electricallyconnecting an electrode pad of the semiconductor chip and the externalelectrode pad via the bending portion.

In accordance with a third aspect of the present invention, there isprovided a semiconductor device comprising a package film on which asemiconductor chip having an electrode pad arranged in a region along acentral portion of the chip or a center line of the chip is mounted,wherein the package film includes: a device hole formed in a regionalong a central portion thereof or a center line thereof incorrespondence with the region where the electrode pad of thesemiconductor chip is formed; an external electrode pad formed in aregion other than the region where the device hole is formed; and aninner lead connecting the electrode pad of the semiconductor chip andthe external electrode pad.

In accordance with a fourth aspect of the present invention, there isprovided a semiconductor device comprising a package film on which asemiconductor chip having an electrode pad arranged in a peripheralportion of the chip is mounted, wherein the package film includes: adevice hole formed in a peripheral portion thereof in correspondencewith the region where the electrode pad of the semiconductor chip isformed; an external electrode pad formed in a region other than theregion where the device hole is formed; and an inner lead connecting theelectrode pad of the semiconductor chip and the external electrode pad,wherein a space between the package film and a surface of thesemiconductor chip is fixed by an encapsulating resin.

In accordance with a fifth aspect of the present invention, there isprovided a semiconductor device comprising a package film including: adevice-mounting film portion on which a semiconductor chip having anelectrode pad arranged in a predetermined region is mounted such thatthe device-mounting film portion faces an obverse surface of thesemiconductor chip; an external-connection film portion arranged on areverse surface of the semiconductor chip and having an externalelectrode pad formed thereon; a bending portion provided between an endportion of the device-mounting film portion and an end portion of theexternal-connection film portion; and an inner lead, wherein thedevice-mounting film portion has a device hole formed in a predeterminedregion in correspondence with a region where an electrode pad of thesemiconductor chip is formed and an external electrode pad formed in aregion other than the region where the device hole is formed, and theinner lead electrically connects the electrode pad of the semiconductorchip and the external electrode pad of the device-mounting film portion,and electrically connects the electrode pad of the semiconductor chipand the external-connection film portion via the bending portion.

In accordance with a sixth aspect of the present invention, there isprovided a method for manufacturing a semiconductor device, comprisingthe steps of: preparing a package film having a planar configurationwhose region is divided into a device-mounting film portion having adevice hole forming therein, an external-connection film portion, and abent portion located between the device-mounting film portion and theexternal-connection film portion, an external electrode pad being formedon the external-connection film portion on a first surface side of thepackage film, an inner lead being formed in such a manner as to leadfrom the device hole to the external electrode pad via the bendingportion; mounting a semiconductor chip on the device-mounting filmportion on the first surface side by bonding the inner lead to anelectrode pad of the semiconductor chip in a region where the devicehole is formed; and bending the external-connection film portion at thebending portion 180° toward a second surface side of the package filmand fixing the same.

In accordance with a seventh aspect of the present invention, there isprovided a method for manufacturing a semiconductor device, comprisingthe steps of: preparing a package film having a planar configurationwhose region is divided into a device-mounting film portion having adevice hole forming therein, an external-connection film portion, and abent portion located between the device-mounting film portion and theexternal-connection film portion, an external electrode pad being formedon the external-connection film portion on a first surface side of thepackage film, an inner lead being formed in such a manner as to leadfrom the device hole to the external electrode pad via the bendingportion; mounting a semiconductor chip on the device-mounting filmportion on a second surface side of the package film by bonding theinner lead to an electrode pad on an obverse surface of thesemiconductor chip in a region where the device hole is formed; andbending the external-connection film portion at the bending portion 180°toward a reverse surface side of the semiconductor chip and fixing thesame to the reverse surface.

In accordance with an eighth aspect of the present invention, there isprovided a method for manufacturing a semiconductor device, comprisingthe steps of: preparing a semiconductor chip having an electrode padarranged in a region along a central portion of the chip or a centerline of the chip, as well as a package film having a device hole formedin a region along a central portion thereof or a center line thereof incorrespondence with the region where the electrode pad of thesemiconductor chip is formed, an external electrode pad being formed onan external connection surface side of the package film in a regionother than the region where the device hole is formed, an inner leadbeing formed in such a manner as to lead from the device hole to theexternal electrode; and mounting the semiconductor chip on a devicemounting surface side of the package film by bonding the inner lead tothe electrode pad of the semiconductor chip in the region where thedevice hole is formed.

In accordance with a ninth aspect of the present invention, there isprovided a method for manufacturing a semiconductor device, comprisingthe steps of: preparing a semiconductor chip having an electrode padarranged in a peripheral portion of the chip, as well as a package filmhaving a device hole formed in a peripheral portion thereof incorrespondence with the region where the electrode pad of thesemiconductor chip is formed, an external electrode pad being formed onan external connection surface side of the package film in a regionother than the region where the device hole is formed, an inner leadbeing formed in such a manner as to lead from the device hole to theexternal electrode; and mounting the semiconductor chip on a devicemounting surface side of the package film by bonding the inner lead tothe electrode pad of the semiconductor chip in the region where thedevice hole is formed, and by allowing an encapsulating resin to flowinto a space between the package film and an obverse surface of thesemiconductor chip.

In accordance with a 10th aspect of the present invention, there isprovided a method for manufacturing a semiconductor device, comprisingthe steps of: preparing a semiconductor chip having electrode padsarranged in a predetermined region thereof, as well as a package filmhaving a planar configuration whose region is divided into adevice-mounting film portion having a device hole forming in adetermined region thereof, an external-connection film portion, and abent portion located between the device-mounting film portion and theexternal-connection film portion, external electrode pads being formedon the external-connection film portion on a first surface side of thepackage film and in a region other than the region where the device holeis formed in the device-mounting film portion on the first surface side,inner leads being formed in such a manner as to lead from the devicehole to respective the external electrode pads; mounting thesemiconductor chip on the device-mounting film portion on a secondsurface side of the package film by bonding the inner leads to theelectrode pads on an obverse surface of the semiconductor chip in aregion where the device hole is formed; and bending theexternal-connection film portion at the bending portion 180° toward areverse surface side of the semiconductor chip and fixing the same tothe reverse surface.

In accordance with an 11th aspect of the present invention, there isprovided a method for mounting a semiconductor device on a mother boardin close contact therewith, comprising the steps of: depositing solderballs on electrode pads of the mother board; and placing thesemiconductor device on the mother board and melting the solder balls soas to electrically connect the electrode pads of the mother board andthe external electrode pads of the semiconductor device.

In accordance with a 12th aspect of the present invention, there isprovided a method for mounting a semiconductor device in which aplurality of superposed semiconductor devices are mounted on a motherboard, comprising the step of: causing the external electrode padsformed on one of the external-connection film portion and thedevice-mounting film portion of a first semiconductor device to besuperposed on the electrode pads of the mother board, and causing theexternal electrode pads formed on one of the external-connection filmportion and the device-mounting film portion of a second semiconductordevice to be superposed on the external electrode pads formed on anotherfilm portion of the first semiconductor device, so as to electricallyconnect the superposed electrodes.

The above and other objects, features and advantages of the presentinvention will become more apparent from the following detaileddescription of the invention when read in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top view, taken from an inner-lead forming surface (firstsurface) side, of a package film used in a semiconductor device inaccordance with a first embodiment of the present invention;

FIG. 1B is a cross-sectional view taken along line A-A′ in FIG. 1A;

FIG. 1C is a cross-sectional structural diagram in the course ofmanufacture of the semiconductor device in accordance with the firstembodiment of the present invention;

FIG. 1D is a cross-sectional structural diagram in the course ofmanufacture of the semiconductor device in accordance with the firstembodiment of the present invention;

FIG. 1E is a cross-sectional structural diagram of the semiconductordevice in accordance with the first embodiment of the present invention;

FIG. 2A is a cross-sectional view of a package film used in asemiconductor device in accordance with a second embodiment of thepresent invention;

FIG. 2B is a cross-sectional structural diagram of the semiconductordevice in accordance with the second embodiment of the presentinvention;

FIG. 3A is an overall cross-sectional view of a semiconductor device inaccordance with a third embodiment of the present invention;

FIG. 3B is an enlarged partial cross-sectional view of a region E shownin FIG. 3A;

FIG. 4A is a cross-sectional structural diagram of a semiconductordevice in accordance with a fourth embodiment of the present inventionin which the semiconductor device in the first embodiment of the presentinvention is provided with a box-shaped protective frame;

FIG. 4B is a cross-sectional structural diagram of the semiconductordevice in accordance with the fourth embodiment of the present inventionin which the semiconductor device in the first embodiment of the presentinvention is provided with a bottomless protective frame;

FIG. 5 is a cross-sectional structural diagram of a semiconductor devicein accordance with a fifth embodiment of the present invention;

FIG. 6 is a cross-sectional structural diagram of a semiconductor devicein accordance with a sixth embodiment of the present invention;

FIG. 7A is a cross-sectional structural diagram of a semiconductordevice in accordance with a seventh embodiment of the present invention;

FIG. 7B is a diagram illustrating the process of manufacturing thesemiconductor device in accordance with the seventh embodiment of thepresent invention;

FIG. 8A is a cross-sectional structural diagram of a semiconductordevice in accordance with an eighth embodiment of the present invention;

FIG. 8B is a diagram illustrating the process of manufacturing thesemiconductor device in accordance with the eighth embodiment of thepresent invention;

FIG. 9A is a front elevational view, taken from the inner-lead formingsurface (first surface) side, of a package film used in a semiconductordevice in accordance with a ninth embodiment of the present invention;

FIG. 9B is a cross-sectional view taken along line A-A′ in FIG. 9A;

FIG. 10 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 10th embodiment of the present invention;

FIG. 11 is a cross-sectional structural diagram of a semiconductordevice in accordance with an 11th embodiment of the present invention;

FIG. 12A is a cross-sectional structural diagram of a semiconductordevice in accordance with a 12th embodiment of the present invention inwhich the semiconductor device in the ninth embodiment of the presentinvention is provided with the box-shaped protective frame;

FIG. 12B is a cross-sectional structural diagram of the semiconductordevice in accordance with the 12th embodiment of the present inventionin which the semiconductor device in the ninth embodiment of the presentinvention is provided with the bottomless protective frame;

FIG. 13 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 13th embodiment of the present invention;

FIG. 14 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 14th embodiment of the present invention;

FIG. 15A is a top view, taken from the inner-lead forming surface (firstsurface) side, of a package film used in a semiconductor device inaccordance with a 15th embodiment of the present invention;

FIG. 15B is a cross-sectional view taken along line A-A′ in FIG. 15A;

FIG. 16A is a cross-sectional structural diagram of a semiconductordevice in accordance with a 16th embodiment of the present invention inwhich the semiconductor device in the 15th embodiment of the presentinvention is provided with the box-shaped protective frame;

FIG. 16B is a cross-sectional structural diagram of the semiconductordevice in accordance with the 16th embodiment of the present inventionin which the semiconductor device in the 15th embodiment of the presentinvention is provided with the bottomless protective frame;

FIG. 17 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 17th embodiment of the present invention;

FIG. 18A is a top view, taken from an external connection surface side,of a package film used in a semiconductor device in accordance with an18th embodiment of the present invention;

FIG. 18B is a cross-sectional view taken along line A-A′ in FIG. 18A;

FIG. 18C is a cross-sectional structural diagram of the semiconductordevice in accordance with the 18th embodiment of the present invention;

FIG. 19A is a top view, taken from the external connection surface side,of a package film used in a semiconductor device in accordance with a19th embodiment of the present invention;

FIG. 19B is a cross-sectional view taken along line A-A′ in FIG. 19A;

FIG. 20 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 20th embodiment of the present invention;

FIG. 21A is a cross-sectional structural diagram of a semiconductordevice in accordance with a 21st embodiment of the present invention inwhich the semiconductor device in the 19th embodiment of the presentinvention is provided with the box-shaped protective frame;

FIG. 21B is a cross-sectional structural diagram of the semiconductordevice in accordance with the 21st embodiment of the present inventionin which the semiconductor device in the 19th embodiment of the presentinvention is provided with the bottomless protective frame;

FIG. 22 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 22nd embodiment of the present invention;

FIG. 23 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 23rd embodiment of the present invention;

FIG. 24 is a fragmentary perspective view of a semiconductor devicehaving a package of the conventional molded type;

FIG. 25 is a cross-sectional structural diagram of a semiconductordevice having a package of the conventional film type;

FIG. 26 is a cross-sectional structural diagram of a semiconductordevice having a package of the conventional flip chip bonding type;

FIG. 27A is a schematic cross-sectional view of an essential portion ofa mother board used in the mounting of a semiconductor device inaccordance with the present invention on a mother board;

FIG. 27B is a cross-sectional structural diagram illustrating themounting of a semiconductor device in accordance with the presentinvention on a mother board; and

FIG. 28 is a cross-sectional structural diagram in which a plurality ofsemiconductor devices in accordance with the present invention arelaminated and mounted on a mother board.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1A to 1E are diagrams illustrating the structure of asemiconductor device and a process for manufacturing the same inaccordance with a first embodiment of the present invention. FIG. 1A isa top view, taken from an inner-lead forming surface (first surface) 1Aside, of a package film 1 used in this semiconductor device. FIG. 1B isa cross-sectional view taken along line A-A′ in FIG. 1A. FIGS. 1C and 1Dare cross-sectional structural diagrams in the course of manufacture ofthe semiconductor device in accordance with the first embodiment. FIG.1E is a cross-sectional structural diagram of the semiconductor devicein accordance with the first embodiment.

First, the package film 1 is fabricated, as shown in FIGS. 1A and 1B.That is, inner leads 3 are formed on a polyimide base resin 2 in which adevice hole 12 has been formed in a predetermined area for adevice-mounting film portion by press punching and in which a bendinghole 13 has been formed in a predetermined area for a bent portion.Here, the inner leads 3 are formed, for instance, by attaching a copperfoil to the surface of the base resin 2, subjecting the copper foil topatterning by photolithographic etching, and then soldering ortin-plating the etched copper foil. Reference numeral 3 a in thedrawings denote dummy inner leads. Next, an insulating resin 4 is coatedon the base thus prepared, electrode pad holes 4 a are formed in theinsulating resin 4 by photolithographic etching to allow the inner leads3 to be exposed, thereby forming external electrode pads 5.Incidentally, the external electrode pads 5 may be formed b selectingcoating (patterning) the insulating resin 4 by a printing method. Inaddition, it is preferable to coat a polyimide-based elastic resin 6 onone surface or both surfaces of the inner leads 3 in a bending portion 1d for the purpose of preventing the deterioration of the strength of theinner leads 3 or disconnection thereof. Thus the package film 1 isfabricated. It should be noted that in a case where the tape automatedbonding (TAB) manufacturing technology, a plurality of package films 1are fabricated and supplied onto a film carrier tape 1 a.

Next, as shown in FIG. 1C, the inner-lead forming surface 1A (firstsurface) of the package film 1 is made to oppose the surface of an LSIchip 8, and the LSI chip 8 is mounted on a device-mounting film portion1 b of the package film 1. That is, in the device-mounting film portion1 b of the package film 1, the inner leads 3 and the dummy inner leads 3a are collectively bonded by thermo-compression bonding to chipelectrode pads 8 a of the LSI chip 8 on which gold-plated bumps 7 havebeen formed. Then, an encapsulating resin 9, such as an epoxy resin, isallowed to flow into a space formed by the device-mounting film portion1 b and the surface of the LSI chip 8, thereby fixing and mounting theLSI chip 8 with respect to the device-mounting film portion 1 b. Here,the dummy inner leads 3 a have the function of preventing the innerleads 3 from becoming disconnected or the bonded portions from becomingpeeled off from the time the inner leads 3 are bonded until the LSI chip8 is fixed. Incidentally, in the case where the TAB technology is used,the package films 1 are separated from the film carrier tape 1 a bypunching after completion of the mounting of the LSI chip 8. Since theinner leads are collectively bonded to the electrode pads of thesemiconductor chip in the above-described manner, the number ofprocessing steps can be reduced, and the manufacturing cost can belowered, so that it possible to lower the cost of the packages.

Next, as shown in FIG. 1D, an external-connection film portion 1 c ofthe package film 1 is bent 180° at the bending portion 1 d toward abase-resin surface 1B (second surface), and is secured to the surface ofthe encapsulating film 9 in the device-mounting film portion 1 b bymeans of an adhesive 10. Here, a point of bending is set, for example,to a position about 1 mm spaced apart from an outer side surface of theLSI chip 8. Finally, as shown in FIG. 1E, solder balls 11 are depositedon the external electrode pads 5.

Thus, in accordance with the first embodiment, the inner leads 3 (andthe dummy inner leads 3 a) formed in such a manner as to project intothe device hole 12 of the device-mounting film portion 1 b arecollectively bonded to the chip electrode pads 8 a of the LSI chip 8 tomount the LSI chip 8 on the device-mounting film portion 1 b, theexternal-connection film portion 1 c is bent 180° at the bending portion1 d (abut 1 mm spaced apart from the outer side of the LSI chip 8) andis secured to the device-mounting film portion 1 b. As a result, since aspecial elastic adhesive is not used, it is possible to improve thereliability. In addition, since the inner leads are collectively bondedto the LSI chip without using an exclusive-use transfer mold, it ispossible to lower the manufacturing cost, so that it is possible tolower the cost of the packages.

It should be noted that a structure may be adopted in which, as shown inFIG. 1D, the solder balls 11 are not deposited on the external electrodepads 5 without executing the step shown in FIG. 1E. When this chip-sizepackage is mounted on a mother board, satisfactory connections are madepossible by supplying solder balls to the mother board side. A printingtechnique, for example, is used in supplying the solder balls to themother board. As the solder balls are thus supplied to the mother boardside, it becomes possible to mount a plurality of packagessimultaneously. Hence, it is possible to reduce the number of steps inthe mounting of packages onto the mother board. In addition, in theprocess for manufacturing the packages, the step for depositing thesolder balls on the external electrode pads is not required, and thenumber of processing steps can be reduced, thereby making it possible tofurther lower the cost of the semiconductor device.

FIGS. 2A and 2B are diagrams illustrating the structure of asemiconductor device and a process for manufacturing the same inaccordance with a second embodiment of the present invention. FIG. 2A isa cross-sectional view of a package film 21 used in this semiconductordevice, and FIG. 2B is a cross-sectional structural diagram of thesemiconductor device in accordance with the second embodiment.

First, the package film 21 is formed, as shown in FIG. 2A. That is, thebase resin 2 is subjected to press punching, thereby forming the devicehole 12, the bending hole 13, and electrode pad holes 2 a for formingexternal electrode pads 22. Then, in the same procedure as that of thefirst embodiment, the inner leads 3 and the dummy inner leads 3 a areformed on this base resin 2, and the insulating resin 4 is coatedthereon. In addition, it is preferable to coat a bending portion 21 dwith the elastic resin 6. Thus the package film 21 having the externalelectrode pads 22 with openings facing a base-resin surface 21B (firstsurface) is fabricated.

Next, as shown in FIG. 2B, the LSI chip 8 is mounted on adevice-mounting film portion 21 b of the package film 21 with thebase-resin surface 21B set on the LSI chip 8 side. Namely, in the sameprocedure as that of the above-described first embodiment, the innerleads 3 and the dummy inner leads 3 a are bonded to the chip electrodepads 8 a of the LSI chip 8 where the bumps 7 have been formed. Then, theLSI chip 8 is fixed and mounted on the device-mounting film portion 21 bby the encapsulating resin 9, and an external-connection film portion 21c is bent 180° at the bending portion 21 d toward an inner-lead formingsurface 21A (second surface), and is secured to the surface of theencapsulating film 9 in the device-mounting film portion 21 b by meansof the adhesive 10. Finally, the solder balls 11 are deposited on theexternal electrode pads 22.

As described above, in accordance with the second embodiment, in theprocess for fabrication of the package film, the electrode pad holes 2 aare formed in advance during the press punching of the device hole 12and the like, and the external electrode pads 22 are formed in theelectrode pad holes 2 a by subjecting the inner leads 3 to patterning.As a result, it is possible to reduce the number of fabrication steps ofthe package film (the number of processing steps of thephotolithographic etching of the insulating resin) and reduce thematerial cost (insulating resin), thereby making it possible to furtherlower the cost of the semiconductor device.

Incidentally, in FIG. 2B, a structure may be adopted in which the solderballs 11 are not deposited on the external electrode pads 22.

A third embodiment of the present invention is characterized in that theinner leads are bonded directly to the electrode pads of the LSI chipwithout forming the bumps. FIGS. 3A and 3B are cross-sectionalstructural diagrams of a semiconductor device in accordance with thethird embodiment of the present invention, in which FIG. 3A is anoverall cross-sectional view, and FIG. 3B is a partial cross-sectionalview of a region E shown in FIG. 3A. It should be noted that thestructure and the manufacturing process other than those described beloware the same as those of the above-described first embodiment.

In FIGS. 3A and 3B, inner leads 31 are formed by subjecting a copperfoil 31 a to gold plating 31 b and by annealing the same at 150° C. for30 minutes or thereabouts (the same holds true of the dummy innerleads). The inner leads 31 and the dummy inner leads are collectivelybonded directly to the chip electrode pads 8 a of the LSI chip 8 bythermo-compression bonding without the bumps.

Generally, if the bumps are not provided, the damage to the electrodepads of the LSI chip is large, and cracks or the like occur below thepads. However, as for the inner leads 31 formed by subjecting the copperfoil 31 a to the gold plating 31 b, their hardness can be lowered byannealing or the like. Hence, by using the softened inner leads 31,direction bonding is made possible in which the damage to the chipelectrode pads is alleviated and cracks or the like do not occur belowthe pads.

Thus, in accordance with the third embodiment, since the process forforming the bumps on the electrode pads of the LSI chip is madeunnecessary, it is possible to reduce the manufacturing cost, therebymaking it possible to lower the cost of the semiconductor device.

Incidentally, it goes without saying that this third embodiment is alsoapplicable to the above-described second embodiment. In addition, it ispossible to adopt the structure in which the solder balls 11 are notdeposited on the external electrode pads 5.

A fourth embodiment of the present invention is characterized in that aprotective frame is provided for protecting the side surfaces and thereverse surface of the LSI chip. FIGS. 4A and 4B are cross-sectionalstructural diagrams illustrating a semiconductor device in accordancewith the fourth embodiment of the present invention. This semiconductordevice is arranged such that the semiconductor device in accordance withthe above-described first embodiment is provided with a box-shapedprotective frame 41 as shown in FIG. 4A or a bottomless protective frame42 as shown in FIG. 4B. The protective frame 41 is provided in such amanner as to cover the side surfaces and the reverse surface of the LSIchip 8, while the protective frame 42 is provided in such a manner as tocover the side surfaces of the LSI chip 8. These protective frames 41and 42 are obtained by forming an insulating material or an electricallyconductive material, such as a resin or a metal, and are fixed to thedevice-mounting film portion 1 b of the package film 1 by means of anadhesive 10 b.

Thus, in accordance with the fourth embodiment, since the protectiveframe 41 or 42 is provided, the side surfaces and the reverse surface ofthe LSI chip 8 can be protected, with the result that it is possible toprevent the occurrence of the breakage of the side surfaces and thereverse surface of the LSI chip 8 during its handling, and animprovement in the yield during mounting can be expected.

Incidentally, it goes without saying that this fourth embodiment is alsoapplicable to the above-described second or third embodiment. Inaddition, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

A fifth embodiment of the present invention is characterized in that aflat plate is provided for improving the flatness of theexternal-connection film portion. FIG. 5 is a cross-sectional structuraldiagram of a semiconductor device in accordance with the fifthembodiment of the present invention. The semiconductor device shown inFIG. 5 is arranged such that, in the semiconductor device in accordancewith the above-described first embodiment, a flat plate 51 formed of aninsulating material or an electrically conductive material such as ametal is provided between the device-mounting film portion 1 b and theexternal-connection film portion 1 c of the package film 1. This flatplate 51 is fixed between the surface of the encapsulating resin 9 ofthe device-mounting film portion 1 b and the external-connection filmportion 1 c by using adhesives 10 a and 10 b. As the procedure forattaching the flat plate 51, after the completion of the step shown inFIG. 1B, for example, the flat plate 51 is fixed to anencapsulating-resin forming portion of the device-mounting film portion1 b by means of the adhesive 10 a, and the external-connection filmportion 1 c is then bent 180° and is fixed to the flat plate 51 by meansof the adhesive 10 b.

Thus, in accordance with the fifth embodiment, since the flat plate 51is provided between the device-mounting film portion 1 b and theexternal-connection film portion 1 c, the flatness of theexternal-connection film portion 1 c and the solder balls 11 can beimproved. Hence, it is possible to improve the mountability of thesemiconductor device onto a mother board. In addition, in the case wherea metal plate or the like is used as the flat plate, it is possible toimprove the heat radiation characteristic of the semiconductor device.

Incidentally, it goes without saying that this fifth embodiment is alsoapplicable to the above-described second, third, or fourth embodiment.In addition, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

A sixth embodiment of the present invention is characterized in that asubstantially U-shaped plate is provided for improving the flatness ofthe external-connection film portion and for protecting the reversesurface of the LSI chip. FIG. 6 is a cross-sectional structural diagramof a semiconductor device in accordance with the sixth embodiment of thepresent invention. The semiconductor device shown in FIG. 6 is arrangedsuch that a substantially U-shaped plate 61 formed substantially into aU shape by using an insulating material or an electrically conductivematerial such as a metal is provided in the semiconductor device inaccordance with the above-described first embodiment. The LSI chip 8 isattached to the inner surface of a bottom plate portion 61 a of thesubstantially U-shaped plate 61 (hence, the device-mounting film portion1 b and the LSI chip 8 are located between the bottom plate 61 a and atop plate portion 61 b), and the external-connection film portion 1 c isattached to the outer surface of the top plate portion 61 b. As theprocedure for attaching the substantially U-shaped plate 61, after thecompletion of the step shown in FIG. 1B, for example, the bottom surfaceof the LSI chip 8 is fixed to the bottom plate portion 61 a by means ofthe adhesive 10 a, and the external-connection film portion 1 c is thenbent 180° and is fixed to the top plate portion 61 b by means of theadhesive 10 b. Alternatively, in the case where the metal plate or thelike is used as the substantially U-shaped plate 61, the LSI chip 8 isfixed to the flat plate, the remaining portion of the flat plate isturned back 180° to form the substantially U-shaped plate 61, and theexternal-connection film portion 1 c is finally bent 180° and is fixedto the top plate portion 61 b. Incidentally, although, in FIG. 6, theorientation of the inner surface of the bending portion 1 d of thepackage film 1 (from right to left) and the orientation of the innersurface of a curved portion 61 c of the substantially U-shaped plate(from left to right) are in a positional relationship of being offsetfrom each other 180° in a plan view, but may be set in a positionalrelationship of being offset from each other 90° in a plan view.

Thus, in accordance with the sixth embodiment, since the arrangementprovided is such that, by using the substantially U-shaped plate 61, theLSI chip 8 is attached to the inner surface of the bottom plate portion61 a thereof, and the external-connection film portion 1 c is attachedto the outer surface of the top plate portion 61 b, it is possible toimprove the flatness of the external-connection film portion 1 c and thesolder balls 11, and protect the LSI chip. In addition, in the casewhere a metal plate or the like is used as the substantially U-shapedplate 61, it is possible to further improve the heat radiationcharacteristic of the package.

Incidentally, it goes without saying that this sixth embodiment is alsoapplicable to the above-described second or third embodiment. Inaddition, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

A seventh embodiment of the present invention is characterized in thatthe external-connection film portion is formed as a two-layeredstructure in which both surfaces are electrically conductive. FIGS. 7Aand 7B are diagrams illustrating the structure of a semiconductor deviceand a manufacturing process in accordance with the seventh embodiment ofthe present invention.

First, as shown in FIG. 7A, a package film 71 having a through hole 2 bfor a reference power supply (grounded power supply) is formed in anexternal-connection film portion 71 c. Namely, when the device hole andthe bending hole are formed in the base resin 2, the through hole 2 b isalso formed simultaneously by press punching, and a reference (grounded)power supply inner lead 3 b is formed in such a manner as to lead to thethrough hole 2 b. Subsequently, the package film 71 is fabricated in thesame procedure as that of the above-described first embodiment. Next, inthe same procedure as that of the above-described first embodiment, theLSI chip 8 is mounted on the package film 71. Then, in the sameprocedure as that of the above-described fifth embodiment, theexternal-connection film portion 71 c is bent, an electricallyconductive flat plate 72 is provided between a device-mounting filmportion 71 b and the external-connection film portion 71 c by means ofthe adhesives 10 a and 10 b, and the adhesive 10 b at the bottom of thethrough hole 2 b is removed.

Next, as shown in FIG. 7B, a solder ball 11 a (electrically conductivematerial) is deposited in the through hole 2 b (at this time, the solderballs 11 are deposited on the external electrode pads 5). Next, thischip-size package is subjected to heat treatment to melt the solder ball11 a, so as to allow the reference power supply inner lead 3 b and theflat plate 72 (serving as the reference power supply) to be electricallyconnected to each other. Incidentally, the volume of the through hole 2b and the volume of the solder ball 11 a should preferably besubstantially identical.

Thus, in accordance with the seventh embodiment, since, on the one hand,the electrically conductive flat plate 72 provided between thedevice-mounting film portion 71 b and the external-connection filmportion 71 c and, on the other hand, the reference power supply innerlead 3 b are electrically connected so as to provide the two-layeredstructure in which both surfaces are electrically conductive, it ispossible to improve the flatness of the external-connection filmportion, improve the heat radiation characteristic of the LSI chip, andreduce the crosstalk noise. Therefore, the operating speed of the LSIchip can be made faster.

Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. Further, the inner leads may be bonded directly tothe chip electrode pads without using bumps as in the above-describedthird embodiment. In addition, an electrically conductive substantiallyU-shaped plate such as the one use in the above-described sixthembodiment may be used without using the electrically conductive flatplate. Still further, it is possible to adopt the structure in which thesolder balls 11 are not deposited on the external electrode pads 5.

An eighth embodiment of the present invention is characterized in thatthe external-connection film portion is bent toward the reverse surfaceof the LSI chip and is fixed thereto. FIGS. 8A and 8B are diagramsillustrating the structure of a semiconductor device and a manufacturingprocess in accordance with the eighth embodiment of the presentinvention. Incidentally, in FIGS. 8A and 8B, those parts and portionswhich are identical to those shown in FIGS. 1 to 7 are denoted by thesame reference numerals.

First, as shown in FIG. 8A, by using the package film 1 in theabove-described first embodiment (see FIGS. 1A and 1B), the LSI chip 8is mounted on the base resin surface 1B of the device-mounting filmportion 1 b in a state in which the base-resin surface 1B (secondsurface) of the package film 1 is set as the LSI chip 8 side. Namely, inthe device-mounting film portion 1 b of the package film 1, the innerleads 3 and the dummy inner leads 3 a are collectively bonded bythermo-compression bonding to the chip electrode pads 8 a of the LSIchip 8 on which the bumps 7 have been formed. Then, the encapsulatingresin 9 is allowed to flow into the space formed by the device-mountingfilm portion 1 b and the surface of the LSI chip 8, thereby fixing andmounting the LSI chip 8 with respect to the device-mounting film portion1 b.

Then, as shown in FIG. 8B, the external-connection film portion 1 c isbent 180° at the bending portion 1 d in such a manner as to besuperposed on a reverse surface 8 b side of the LSI chip 8, and issecured to the reverse surface 8 b of the chip by means of the adhesive10. Finally, the solder balls 11 are deposited on the external electrodepads 5.

Thus, in accordance with the eighth embodiment, since theexternal-connection film portion 1 c is bent toward the reverse surface8 b of the LSI chip 8 and is secured thereto, it is possible to protectthe reverse surface 8 b and the side surfaces of the LSI chip 8 withoutusing a protective frame or the like. In addition, it is possible toflatten the external-connection film portion 1 c without using a flatplate. Furthermore, it is possible to lower the cost of thesemiconductor device and improve its reliability.

Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. In this case, the inner-lead forming surface of theexternal-connection film portion is bonded to the reverse surface of theLSI chip 8. Further, the inner leads may be bonded directly to the chipelectrode pads 8 a without using bumps as in the above-described thirdembodiment. Furthermore, it is possible to adopt the structure in whichthe solder balls 11 are not deposited on the external electrode pads 5.

A ninth embodiment of the present invention is characterized in that thepackage film having external-connection film portions on both sides ofthe device-mounting film portion is used, and these external-connectionfilm portions are respectively bent. FIGS. 9A and 9B are diagramsillustrating the structure of a semiconductor device and a manufacturingprocess in accordance with the ninth embodiment of the presentinvention. FIG. 9A is a front elevational view in which a package film91 used in this semiconductor device is viewed from the inner-leadforming surface. FIG. 9B is a cross-sectional structural view, takenalong line A-A′ of FIG. 9A, of the semiconductor device in accordancewith the ninth embodiment. Incidentally, in FIGS. 9A and 9B, those partsand portions which are identical to those shown in FIGS. 1 to 8 aredenoted by the same reference numerals.

First, the package film 91 shown in FIG. 9A is fabricated by the sameprocedure as that of the above-described first embodiment. Namely, theinner leads 3 are formed by effecting patterning on the base resin 2 inwhich the device hole 12 and two bending holes 13 a and 13 b have beenformed. Then, the insulating resin 4 is formed by effecting patterningthereon, thereby forming the external electrode pads 5. It should benoted that dummy inner leads are unnecessary. In addition, the elasticresin 6 should preferably be coated to prevent the deterioration of thestrength of the inner leads 3 in bending portions 91 d and 91 f(portions where the bending holes 13 a and 13 b are formed). The packagefilm 1 is fabricated in the above-described manner.

Next, as shown in FIG. 9B, the LSI chip 8 is mounted on adevice-mounting film portion 91 b in a state in which an inner-leadforming surface 91A (first surface) of a device-mounting film portion 91b of the package film 91 faces the surface of the LSI chip 8. Namely, inthe device-mounting film portion 91 b of the package film 91, the innerleads 3 are collectively bonded by thermo-compression bonding to thechip electrode pads 8 a of the LSI chip 8 on which the bumps 7 have beenformed. Then, the encapsulating resin 9 is allowed to flow into thespace formed by the device-mounting film portion 91 b and the surface ofthe LSI chip 8, thereby fixing and mounting the LSI chip 8 with respectto the device-mounting film portion 91 b. Next, external-connection filmportions 91 c and 91 e are respectively bent 180° at the bendingportions 91 d and 91 f in such a manner as to be superposed on abase-resin surface 91B (second surface) of the device-mounting filmportion 91 b, and are secured to the surface of the encapsulating resin9 by means of the adhesives 10 a and 10 b. Finally, the solder balls 11are deposited on the external electrode pads 5.

Thus, in accordance with the ninth embodiment, since theexternal-connection film portions 91 c and 91 e are provided on bothsides of the device-mounting film portion 91 b, the length of the wiring(inner leads) from each chip electrode pad to each correspondingexternal electrode pad can be made shorter than in the above-describedfirst embodiment, so that more efficient routing of the wiring becomespossible. Hence, the operating speed of the LSI chip can be made faster.

Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. In this case, the LSI chip 8 is fixedly mounted inthe state in which the base-resin surface side of the device-mountingfilm portion faces the surface of the LSI chip 8. Furthermore, it ispossible to adopt the structure in which the solder balls 11 are notdeposited on the external electrode pads 5.

A 10th embodiment of the present invention is characterized in thatafter the external-connection film portions formed on both side of thepackage film are bent, the encapsulating resin is allowed to flow in,and the LSI chip is mounted on the package film. FIG. 10 is across-sectional structural view illustrating a semiconductor device inaccordance with the 10th embodiment of the present invention.Incidentally, in FIG. 10, those parts and portions which are identicalto those shown in FIGS. 1 to 9 are denoted by the same referencenumerals.

First, by using the package film 91 (see FIG. 9A) in accordance with theabove-described ninth embodiment, the inner-lead forming surface 91A(first surface) of the package film 91 is set as the LSI chip 8 side. Inthe device-mounting film portion 91 b of the package film 91, the innerleads 3 and the dummy inner leads 3 a are collectively bonded bythermo-compression bonding to the chip electrode pads 8 a of the LSIchip 8 on which the bumps 7 have been formed. Then, theexternal-connection film portions 91 c and 91 e are respectively bent180° at the bending portions 91 d and 91 f in such a manner as to besuperposed on the base-resin surface 91 side.

Next, the encapsulating resin 9 is injected into a gap 91 g formedbetween the external-connection film portions 91 c and 91 e, with theresult that the LSI chip 8 is fixed and mounted on the device-mountingfilm portion 91 b, and the bent external-connection film portions 91 cand 91 e are fixed to the device-mounting film portion 91 b. Finally,the solder balls 11 are deposited on the external electrode pads 5.

Thus, in accordance with the 10th embodiment, since theexternal-connection film portions 91 c and 91 e are bent, and theencapsulating resin 9 is injected into the gap 91 g between theseexternal-connection film portions to fix and mount the LSI chip 8 andfix the external-connection film portion 91 c and 91 e, the adhesive forfixing the external-connection film portions as well as the step forfixing the external-connection film portions by the adhesive are madeunnecessary. Hence, it is possible to further lower the manufacturingcost.

Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. Furthermore, it is possible to adopt the structure inwhich the solder balls 11 are not deposited on the external electrodepads 5.

An 11th embodiment of the present invention is characterized in that theinner leads formed on the package film having external-connection filmportions on both sides of the device-mounting film portion are bondeddirectly on the electrode pads of the LSI chip without forming thebumps. FIG. 11 is a cross-sectional structural view illustrating asemiconductor device in accordance with the 11th embodiment of thepresent invention. Incidentally, in FIG. 11, those parts and portionswhich are identical to those shown in FIGS. 1 to 10 are denoted by thesame reference numerals.

First, a package film 111 is fabricated. This package film 111 isarranged such that, in the package film 91 (see FIG. 9A) in accordancewith the above-described ninth embodiment, not the inner leads 3 but theinner leads 31 in which the copper foil used in the above-describedthird embodiment is provided with gold plating are formed by patterning.To lower the hardness of the inner leads 31, in the same way as in theabove-described third embodiment, annealing at 150° C. for 30 minutes orthereabouts is carried out. The inner leads 31 are collectively bondeddirectly to the chip electrode pads 8 a of the LSI chip 8 bythermo-compression bonding without the bumps. Incidentally, the othermanufacturing process is similar to that of the above-described ninthembodiment.

Thus, in accordance with the 11th embodiment, since the step for formingbumps on the electrode pads of the LSI chip becomes unnecessary, it ispossible to reduce the manufacturing cost more than in theabove-described ninth embodiment, thereby making it possible to furtherlower the cost of the semiconductor device.

Incidentally, it goes without saying that this 11th embodiment is alsoapplicable to the above-described 10th embodiment. In addition, it ispossible to adopt the structure in which the solder balls 11 are notdeposited on the external electrode pads 5.

A 12th embodiment of the present invention is characterized in that aprotective frame for protecting the side surfaces and the reversesurface of the LSI chip is provided on the semiconductor device having astructure in which two external-connection film portions formed on bothside of the package film are bent. FIGS. 12A and 12B are cross-sectionalstructural views illustrating a semiconductor device in accordance withthe 12th embodiment of the present invention. Incidentally, in FIGS. 12Aand 12B, those parts and portions which are identical to those shown inFIGS. 1 to 11 are denoted by the same reference numerals.

The semiconductor device in accordance with the 12th embodiment isarranged such that the semiconductor device in accordance with theabove-described ninth embodiment is provided with the box-shapedprotective frame 41 shown in FIG. 12A or the bottomless protective frame42 shown in FIG. 12B. These protective frames 41 and 42 are the same asthose used in the above-described fourth embodiment, and are fixed tothe device-mounting film portion 91 b of the package film 91 by means ofan adhesive 10 c.

Thus, in accordance with the 12th embodiment, since the semiconductordevice having the structure in which the two external-connection filmportions are bent is provided with the protective frame 41 or 42, theside surfaces and the reverse surface of the LSI chip 8 can beprotected, with the result that it is possible to prevent the occurrenceof the breakage of the side surfaces and the reverse surface of the LSIchip 8 during its handling, and an improvement in the yield duringmounting can be expected.

Incidentally, it goes without saying that this 12th embodiment is alsoapplicable to the above-described 10th or 11th embodiment. In addition,it is possible to adopt the structure in which the solder balls 11 arenot deposited on the external electrode pads 5.

A 13th embodiment of the present invention is characterized in that aplate is provided for improving the flatness of external-connection filmportions which are formed on both sides of the package film and arerespectively bent when the LSI chip is mounted on the package film. FIG.13 is a cross-sectional structural view illustrating a semiconductordevice in accordance with the 13th embodiment of the present invention.Incidentally, in FIG. 13, those parts and portions which are identicalto those shown in FIGS. 1 to 12 are denoted by the same referencenumerals.

The semiconductor device shown in FIG. 13 is arranged such that, in thesemiconductor device in accordance with the above-described ninthembodiment, the flat plate 51 formed of an insulating material or anelectrically conductive material such as a metal, which is used in theabove-described fifth embodiment, is provided between thedevice-mounting film portion 91 b of the package film 91 and theexternal-connection film portions 91 c and 91 e. This flat plate 51 isfixed between the surface of the encapsulating resin 9 of thedevice-mounting film portion 91 b and the external-connection filmportions 91 c and 91 e by using the adhesives 10 a, 10 b, and 10 c.

Thus, in accordance with the 13th embodiment, since the flat plate 51 isprovided between the device-mounting film portion 91 b and theexternal-connection film portions 91 c and 91 e, the flatness of theexternal-connection film portions 91 c and 91 e, i.e., the flatness ofthe solder balls 11, can be improved, thereby making it possible toimprove the mountability of the semiconductor device onto a motherboard. In addition, in the case where a metal plate or the like is usedas the flat plate, it is possible to improve the heat radiationcharacteristic of the semiconductor device.

Incidentally, it goes without saying that this 13th embodiment is alsoapplicable to the above-described 11th or 12th embodiment. In addition,it is possible to adopt the structure in which the solder balls 11 arenot deposited on the external electrode pads 5. Furthermore, asubstantially U-shaped plate such as the one used in the above-describedsixth embodiment may be used instead of using the flat plate.

Further, by using an electrically conductive flat plate or substantiallyU-shaped plate, in the same way as in the above-described seventhembodiment, the external-connection film portions may be formed as thetwo-layered structure in which both surfaces are electricallyconductive, wherein a reference power supply inner lead is formed on thepackage film 91, through holes are respectively provided in theexternal-connection film portions 91 c and 91 e, and the reference powersupply inner lead and the electrically conductive flat plate orsubstantially U-shaped plate are electrically connected via thesethrough holes. Consequently, since the crosstalk noise can be reduced,the operating speed of the LSI chip can be made even faster.

A 14th embodiment of the present invention is characterized in that theexternal-connection film portions formed on both sides of the packagefilm are respectively bent toward the reverse surface of the LSI chipand are fixed thereto. FIG. 14 is a diagram illustrating the structureof a semiconductor device in accordance with the 14th embodiment of thepresent invention. Incidentally, in FIG. 14, those parts and portionswhich are identical to those shown in FIGS. 1 to 13 are denoted by thesame reference numerals.

First, as shown in FIG. 14, by using the package film 91 in theabove-described ninth embodiment (see FIG. 9A), the LSI chip 8 ismounted on the device-mounting film portion 91 b in a state in which thebase-resin surface 91B (second surface) of the device-mounting filmportion 91 b of the package film 91 faces the surface of the LSI chip 8.Namely, in the device-mounting film portion 91 b of the package film 91,the inner leads 3 are collectively bonded by thermo-compression bondingto the chip electrode pads 8 a of the LSI chip 8 on which the bumps 7have been formed. Then, the encapsulating resin 9 is allowed to flowinto the space formed by the device-mounting film portion 91 b and thesurface of the LSI chip 8, thereby fixing and mounting the LSI chip 8with respect to the device-mounting film portion 91 b.

Next, the external-connection film portions 91 c and 91 e arerespectively bent 180° at the bending portions 91 d and 91 f in such amanner as to be superposed on the reverse surface 8 b side of the LSIchip 8, and are secured to the reverse surface 8 b of the chip by meansof the adhesives 10 a and 10 b. Finally, the solder balls 11 aredeposited on the external electrode pads 5.

Thus, in accordance with the 14th embodiment, since theexternal-connection film portions 91 c and 91 e are bent toward thereverse surface 8 b of the LSI chip 8 and are secured thereto, it ispossible to protect the reverse surface 8 b and the side surfaces of theLSI chip 8 without using a protective frame or the like. In addition, itis possible to flatten the external-connection film portions 91 c and 91e without using a flat plate.

Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. In this case, the inner-lead forming surface of theexternal-connection film portion is bonded to the reverse surface of theLSI chip 8. Further, the inner leads may be bonded directly to the chipelectrode pads 8 a without using bumps as in the above-described thirdand 11th embodiments. Furthermore, it is possible to adopt the structurein which the solder balls 11 are not deposited on the external electrodepads 5.

A 15th embodiment of the present invention is characterized in that thepackage film having external-connection film portions on four sides ofthe device-mounting film portion is used, and these external-connectionfilm portions are respectively bent. FIGS. 15A and 15B are diagramsillustrating the structure of a semiconductor device and a manufacturingprocess in accordance with the 15th embodiment of the present invention.FIG. 15A is a front elevational view in which a package film 151 used inthis semiconductor device is viewed from a inner-lead forming surface151A. FIG. 15B is a cross-sectional structural view, taken along lineA-A′ of FIG. 15A, of the semiconductor device in accordance with the15th embodiment. Incidentally, in FIGS. 15A and 15B, those parts andportions which are identical to those shown in FIGS. 1 to 14 are denotedby the same reference numerals.

First, the package film 151 shown in FIG. 15A is fabricated by the sameprocedure as that of the above-described first embodiment. Namely, theinner leads 3 are formed by effecting patterning on the base resin 2 inwhich the device hole 12 has been formed and a bending hole 13 c hasbeen formed in the shape of a frame in such a manner as to surround thedevice hole 12. Then, the insulating resin 4 is formed by effectingpatterning thereon, thereby forming the external electrode pads 5. Itshould be noted that dummy inner leads are unnecessary. In addition, theelastic resin 6 should preferably be coated to prevent the deteriorationof the strength of the inner leads 3 in bending portions 151 d, 151 f,151 j, and 151 k (portions which respectively correspond to the foursides of the bending hole 13 c formed in the shape of a square frame).The package film 151 is fabricated in the above-described manner.

Next, as shown in FIG. 15B, the LSI chip 8 is mounted on adevice-mounting film portion 151 b in a state in which the inner-leadforming surface 151A (first surface) of the device-mounting film portion151 b of the package film 151 faces the surface of the LSI chip 8.Namely, in the device-mounting film portion 151 b of the package film151, the inner leads 3 are collectively bonded by thermo-compressionbonding to the chip electrode pads 8 a of the LSI chip 8 on which thebumps 7 have been formed. Then, the encapsulating resin 9 is allowed toflow into the space formed by the device-mounting film portion 151 b andthe surface of the LSI chip 8, thereby fixing and mounting the LSI chip8 with respect to the device-mounting film portion 151 b. Next,external-connection film portions 151 c, 151 e, 151 h, and 151 i arerespectively bent 180° at the bending portions 151 d, 151 f, 151 j, and151 k in such a manner as to be superposed on a base-resin surface 151B(second surface) of the device-mounting film portion 151 b, and aresecured to the surface of the encapsulating resin 9 by means of theadhesives 10 a and 10 b. Finally, the solder balls 11 are deposited onthe external electrode pads 5.

Thus, in accordance with the 15th embodiment, since theexternal-connection film portions are respectively provided on the foursides of the device-mounting film portion 151 b, the length of thewiring (inner leads) from each chip electrode pad to each correspondingexternal electrode pad can be made shorter than in the above-describedninth embodiment, so that more efficient routing of the wiring becomespossible. Hence, the operating speed of the LSI chip can be made faster.

It should be noted that an arrangement may be provided such that, in thesame way as in the above-described 10th embodiment, the fourexternal-connection film portions are bent, and the encapsulating resin9 is allowed to flow into the gap at the bent portions. Further, theinner leads may be bonded directly to the chip electrode pads 8 awithout using bumps as in the above-described third and 11thembodiments. Furthermore, it is possible to adopt the structure in whichthe solder balls 11 are not deposited on the external electrode pads 5.

A 16th embodiment of the present invention is characterized in that thesemiconductor device having the structure in which fourexternal-connection film portions are bent is provided with a protectiveframe for protecting the side surfaces and the reverse surface of theLSI chip or a flat plate for improving the flatness of the bentexternal-connection film portions. FIGS. 16A and 16B are cross-sectionalstructural views illustrating a semiconductor device in accordance withthe 16th embodiment of the present invention. Incidentally, in FIGS. 16Aand 16B, those parts and portions which are identical to those shown inFIGS. 1 to 15 are denoted by the same reference numerals.

The semiconductor device in accordance with the 16th embodiment isarranged such that the semiconductor device in accordance with theabove-described 15th embodiment is provided with the box-shapedprotective frame 41 shown in FIG. 16A or the bottomless protective frame42 shown in FIG. 16B. These protective frames 41 and 42 are the same asthose used in the above-described fourth embodiment, and are fixed tothe device-mounting film portion 151 b of the package film 151 by meansof an adhesive 10 c.

Thus, in accordance with the 16th embodiment, since the semiconductordevice having the structure in which the four external-connection filmportions are bent is provided with the protective frame 41 or 42, theside surfaces and the reverse surface of the LSI chip 8 can beprotected, with the result that it is possible to prevent the occurrenceof the breakage of the side surfaces and the reverse surface of the LSIchip 8 during its handling, and an improvement in the yield duringmounting can be expected.

It should be noted that, instead of using the protective film 41 or 42,it is possible to adopt an arrangement in which a flat plate such as theone used in the above-described fifth embodiment is provided between thefour external-connection film portions and the surface of theencapsulating resin 9, or an arrangement in which both the protectivefilm 41 or 42 and the aforementioned flat plate are provided. Further,by using an electrically conductive flat plate, in the same way as inthe above-described seventh embodiment, the external-connection filmportions may be formed as the two-layered structure in which bothsurfaces are electrically conductive, wherein a reference power supplyinner lead is formed on the package film 151, through holes arerespectively provided in the four external-connection film portions, andthe reference power supply inner lead and the electrically conductiveflat plate are electrically connected via these through holes.Furthermore, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

A 17th embodiment of the present invention is characterized in that theexternal-connection film portions formed on the four sides of thepackage film are respectively bent toward the reverse surface of the LSIchip and are fixed thereto. FIG. 17 is a diagram illustrating thestructure of a semiconductor device in accordance with the 17thembodiment of the present invention. Incidentally, in FIG. 17, thoseparts and portions which are identical to those shown in FIGS. 1 to 16are denoted by the same reference numerals.

First, as shown in FIG. 17, by using the package film 151 in theabove-described 15th embodiment (see FIG. 15A), the LSI chip 8 isfixedly mounted on the device-mounting film portion 151 b in the sameprocedure as that of the above-described 14th embodiment in the state inwhich the base-resin surface 151B (second surface) of thedevice-mounting film portion 151 b of the package film 151 faces thesurface of the LSI chip 8. Next, the four external-connection filmportions including the external-connection film portions 151 c and 151 eare respectively bent 180° at the four bending portions including thebending portions 151 d and 151 f in such a manner as to be superposed onthe reverse surface 8 b side of the LSI chip 8, and are secured to thereverse surface 8 b of the chip by means of the adhesives 10 a and 10 b.Finally, the solder balls 11 are deposited on the external electrodepads 5.

Thus, in accordance with the 17th embodiment, since the fourexternal-connection film portions are bent toward the reverse surface 8b of the LSI chip 8 and are secured thereto, it is possible to protectthe reverse surface 8 b and the side surfaces of the LSI chip 8 withoutusing a protective frame or the like. In addition, it is possible toflatten the external-connection film portions without using a flatplate.

Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. In this case, the inner-lead forming surface of theexternal-connection film portion is bonded to the reverse surface of theLSI chip 8. Further, the inner leads may be bonded directly to the chipelectrode pads 8 a without using bumps as in the above-described thirdembodiment. Furthermore, it is possible to adopt the structure in whichthe solder balls 11 are not deposited on the external electrode pads 5.

An 18th embodiment of the present invention is characterized in that anLSI chip in which the chip electrode pads are formed in the vicinity ofa center line on the chip surface is used. FIGS. 18A to 18C are diagramsillustrating the structure of a semiconductor device and a manufacturingprocess in accordance with the 18th embodiment of the present invention.FIG. 18A is a plan view of an external connection surface 181A of apackage film 181 used in this semiconductor device. FIG. 18B is across-sectional structural view taken along line A-A′ of FIG. 18A. FIG.18C is a cross-sectional structural diagram of this semiconductordevice. Incidentally, in FIGS. 18A to 18C, those parts and portionswhich are identical to those shown in FIGS. 1 to 17 are denoted by thesame reference numerals.

As shown in FIGS. 18A and 18B, with respect to an LSI chip 182 in whichchip electrode pads 182 a are formed in a region along a chip centerline F, the package film 181 having a device hole 183 in a region alongthe center line F is fabricated in correspondence with the region of theLSI 182 where the chip electrode pads are formed, in the same procedureas that of the above-described second embodiment. At this time, thebending hole is not formed, and the size of the package film 181 is setto be substantially identical as the size of the LSI chip.

Next, as shown in FIG. 18C, in the same procedure as that of theabove-described second embodiment, the inner leads 3 are bonded to thechip electrode pads 182 a of the LSI chip 182, the LSI chip 182 ismounted on the package film 181 (however, there is no step for bendingthe package film), and the solder balls 11 are deposited on the externalelectrode pads 22.

Thus, in accordance with the 18th embodiment, since the LSI chip 182 inwhich the chip electrode pads 182 a are formed along the chip centerline is mounted on the package film 181 having the device hole 183 atthe position corresponding to the chip-electrode-pad forming region andhaving substantially the same size as the LSI chip 182, a specialelastic adhesive and a substrate whose coefficient of thermal expansiondiffers from that of the LSI chip are not used, it is possible toimprove the reliability of the semiconductor device. In addition, it ispossible to reduce the number of processing steps (the number of bendingsteps of the package film) and reduce the material cost, thereby makingit possible to further lower the cost of the semiconductor device.Moreover, a more compact and lightweight semiconductor device can berealized as compared with the above-described first embodiment.

It should be noted that the inner leads may be bonded directly to thechip electrode pads as in the above-described third embodiment.Furthermore, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 22.

A 19th embodiment of the present invention is characterized in that anLSI chip in which the chip electrode pads are formed in a centralportion of the chip surface is used. FIGS. 19A and 19B are diagramsillustrating the structure of a semiconductor device and a manufacturingprocess in accordance with the 19th embodiment of the present invention.FIG. 19A is a plan view of an external connection surface 191A of apackage film 191 used in this semiconductor device. FIG. 19B is across-sectional structural view, taken along line A-A′ of FIG. 19A, ofthe semiconductor device in accordance with the 19th embodiment.Incidentally, in FIGS. 19A and 19B, those parts and portions which areidentical to those shown in FIGS. 1 to 18 are denoted by the samereference numerals.

First, as shown in FIG. 19A, with respect to an LSI chip 192 in whichchip electrode pads 192 a are formed in a vicinity of a central portionof the chip, the package film 191 having a device hole 193 in itscentral portion is fabricated in correspondence with the region of theLSI 192 where the chip electrode pads are formed, in the same procedureas that of the above-described first embodiment. The size of the packagefilm 191 is set to be substantially identical as the size of the LSIchip 192. In addition, the position and shape of the device hole 193 areset to correspond to those of the chip-electrode-pad forming region ofthe LSI chip 192. In the package film 191, the external electrode pads 5are formed on the inner-lead forming surface side, and the inner-leadforming surface is used as the external connection surface 191A.Meanwhile, the resin surface of the package film 191 is used as a devicemounting surface 191B which is the side where the LSI chip 191 ismounted.

Next, as shown in FIG. 19C, in the same procedure as that of theabove-described first embodiment, the inner leads 3 are collectivelybonded to the chip electrode pads 192 a of the LSI chip 192, the LSIchip 192 is mounted on the device mounting surface 191B side of thepackage film 191 (however, there is no step for bending the packagefilm), and the solder balls 11 are deposited on the external electrodepads 5.

Thus, in accordance with the 19th embodiment, since the LSI chip 192 inwhich the chip electrode pads 192 a are formed on the central portion ofthe chip is mounted on the package film 191 having the device hole 193at a position corresponding to the chip-electrode-pad forming region andhaving substantially the same size as that of the LSI chip 192, aspecial elastic adhesive and a substrate whose coefficient of thermalexpansion differs from that of the LSI chip are not used, and it ispossible to improve the reliability of the semiconductor device. Inaddition, it is possible to reduce the number of processing steps (thenumber of bending steps of the package film) and reduce the materialcost, thereby making it possible to further lower the cost of thesemiconductor device. Moreover, a more compact and lightweightsemiconductor device can be realized as compared with theabove-described first embodiment.

It should be noted that the inner leads may be bonded directly to thechip electrode pads as in the above-described third embodiment.Furthermore, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

A 20th embodiment of the present invention is characterized in that apackage film having insulating resin projections on the device mountingsurface is used in the above-described 18th or 19th embodiment. FIG. 20is a cross-sectional view illustrating the structure of a semiconductordevice in accordance with the 20th embodiment of the present invention.Incidentally, in FIG. 20, those parts and portions which are identicalto those shown in FIGS. 1 to 19 are denoted by the same referencenumerals.

The semiconductor device shown in FIG. 20 is arranged such that not thepackage film 181 but a package film 201 having insulating resinprojections on the device mounting surface is used in the semiconductordevice in accordance with the 18th embodiment. Insulating resinprojections 202 are provided on a device mounting surface 201B of thepackage film 201. These insulating resin projections 202 can be easilyformed by coating the base resin 2 with the inner leads 3 patternedthereon with an insulating resin, and by subjecting this insulatingresin to photolithographic etching.

Next, in the same procedure as that of the above-described 18thembodiment, the inner leads 3 are bonded to the chip electrode pads 182a of the LSI chip 182, and the encapsulating resin 9 is allowed to flowinto the space between the surface of the LSI chip 182 and the packagefilm 201, thereby fixing and mounting the LSI chip 182. At this time,the encapsulating resin 9 is allowed to flow in by arranging the packagefilm 201 and the LSI chip 182 such that top portions 202 a of theinsulating resin projections 202 abut against the surface of the LSIchip 182. In addition, the insulating resin projections 202 have thefunction of making the encapsulating resin 9 to flow and of improvingthe flatness of the package film 201.

Thus, in accordance with the 20th embodiment, since the insulating resinprojections 202 are provided on the device mounting surface 201B of thepackage film 201, the flow of the encapsulating resin 9 is facilitated,and it is possible to improve the flatness of the package film 201,thereby making it possible to improve the quality of the package.

Incidentally, it goes without saying that this 20th embodiment is alsoapplicable to the above-described 19th embodiment. In addition, it ispossible to adopt the structure in which the solder balls 11 are notdeposited on the external electrode pads 5.

A 21st embodiment of the present invention is characterized in that thesemiconductor device using a package film having a device hole formed ina region along its central portion or its center line is provided with aprotective frame for protecting the side surfaces and the reversesurface of the LSI chip. FIGS. 21A and 21B are cross-sectionalstructural views illustrating a semiconductor device in accordance withthe 21st embodiment of the present invention. Incidentally, in FIGS. 21Aand 21B, those parts and portions which are identical to those shown inFIGS. 1 to 20 are denoted by the same reference numerals.

The semiconductor device in accordance with the 21st embodiment isarranged such that the semiconductor device in accordance with theabove-described 19th embodiment is provided with a box-shaped protectiveframe 211 shown in FIG. 21A or a bottomless protective frame 212 shownin FIG. 21B. These protective frames 211 and 212 are fixed to the devicemounting surface 191B of the package film 191 by using the adhesive 10.

Thus, in accordance with the 21st embodiment, since the protective frame211 or 212 is provided, the side surfaces and the reverse surface of theLSI chip 192 can be protected, with the result that it is possible toprevent the occurrence of the breakage of the side surfaces and thereverse surface of the LSI chip 192 during its handling, and animprovement in the yield during mounting can be expected.

Incidentally, it goes without saying that this 21st embodiment is alsoapplicable to the above-described 18th or 20th embodiment. In addition,it is possible to adopt the structure in which the solder balls 11 arenot deposited on the external electrode pads 5.

FIG. 22 is a cross-sectional structural diagram illustrating asemiconductor device in accordance a 22nd embodiment of the presentinvention. Incidentally, in FIG. 22, those parts and portions which areidentical to those shown in FIGS. 1 to 21 are denoted by the samereference numerals.

The semiconductor device shown in FIG. 22 is comprised of a package film221 and the LSI chip 192 used in the above-described 19th embodiment.The package film 221 is arranged such that four external-connection filmportions including external-connection film portions 221 c and 221 h areprovided on the four sides of a device-mounting film portion 221 b viafour bending portions including bending portions 221 d and 221 i as inthe case of the package film 151 (see FIG. 15A) in accordance with theabove-described 15th Embodiment.

First, the package film 221 is fabricated. Namely, in the same procedureas that of the above-described first embodiment, the inner leads 3 areformed by effecting patterning on the base resin 2 in which the devicehole 193 has been formed in its central portion in correspondence withthe chip-electrode-pad forming region of the LSI chip 192 and a bendinghole has been formed in the shape of a frame in such a manner as tosurround the device hole 193. Then, the insulating resin 4 is formed byeffecting patterning thereon, thereby forming the external electrodepads 5. The external electrode pads 5 are formed also on the inner-leadforming surface (first surface) of the device-mounting film portion 221b. The device-mounting film portion 221 b has the same structure as thatof the package film 191 in accordance with the above-described 19thembodiment (see FIG. 19A), and the package film 221 has the structure inwhich four external-connection film portions are provided in the packagefilm 191 in accordance with the above-described 19th embodiment(however, the device hole 193 in the device-mounting film portion 221 bis illustrated as the device hole 193 in the package film 191 which hasbeen rotated 45°). Incidentally, the elastic resin 6 should preferablybe coated to prevent the deterioration of the strength of the innerleads 3 in the four bending portions. The package film 221 is fabricatedin the above-described manner.

Next, in the same way as in the above-described 19th embodiment, the LSIchip 192 is mounted on the device-mounting film portion 221 b in a statein which the base resin surface (second surface) of the device-mountingfilm portion 221 b faces the surface of the LSI chip 192. Namely, theinner leads 3 are collectively bonded by thermo-compression bonding tothe chip electrode pads 192 a of the LSI chip 192 on which the bumps 7have been formed. Then, the encapsulating resin 9 is allowed to flowinto the space formed by the device-mounting film portion 221 b and thesurface of the LSI chip 192, thereby fixing and mounting the LSI chip192 on the device-mounting film portion 221 b.

Next, the four external-connection film portions (theexternal-connection film portions 221 c, 221 h, etc.) are respectivelybent 180° at the four bending portions (bending portions 221 d, 221 j,etc.) in such a manner as to be superposed on a reverse surface 192 b ofthe LSI chip 192, and are secured to the reverse surface 192 b of thechip by means of the adhesives 10 a, 10 b, and the like. Finally, thesolder balls 11 are respectively deposited on the external electrodepads 5 on the four external-connection film portions. Here, the solderballs 11 are not deposited on the external electrode pads 5 of thedevice-mounting film portion 221 b.

As for the semiconductor device shown in FIG. 22, a plurality ofsemiconductor devices can be laminated. The number of the semiconductordevices to be laminated is assumed to be N (N is an integer equal to orgreater than 2). The external-connection film portions of a firstsemiconductor device and the device-mounting film portion 221 b of asecond semiconductor device are made to face each other, and the twosemiconductor devices are laminated in such a manner that the respectiveexternal electrode pads 5 are superposed on each other. Then, the solderballs 11 deposited on the external electrode pads 5 of the firstsemiconductor device are melted to electrically connect the superposedexternal electrodes. As a result, the second semiconductor device islaminated and fixed on the first semiconductor device. Similarly, thirdto Nth semiconductor devices are laminated. The melting of the solderballs 11 may be effected collectively after the N semiconductor deviceshave been superposed one on top of another. However, in the case wherethe external-connection film portions of the first semiconductor deviceand the device-mounting film portion 221 b of the second semiconductordevice are made to face each other in the above-described manner, it isnecessary to form the external electrode pads 5 of theexternal-connection film portions in such a manner as to correspond tothe positions where the external electrode pads 5 of the device-mountingfilm portion 221 b are formed. Incidentally, the semiconductor devicesmay be laminated in a state in which the device-mounting film portions221 b or the external-connection film portions of the respectivesemiconductor devices are made to face each other. It goes withoutsaying that a plurality of the semiconductor devices shown in FIG. 22can be laminated and mounted on a mother board in the same procedure asthe one described above.

Thus, in accordance with the 22nd embodiment, since the externalelectrode pads 5 are also provided on the device-mounting film portion221 b, and the external-connection film portions are fixed to thereverse surface of the LSI chip, it is possible to reduce the wiringlength, protect the reverse surface of the LSI chip, and flatten theexternal-connection film portions, and the laminated mounting on themother board (three-dimensional mounting) becomes possible. Hence, itbecomes possible to reduce the mounting space in the mother board.Further, it is possible to lower the cost of the semiconductor devicesand improve the reliability.

It should be noted that two external-connection film portions may beprovided on both sides of the device-mounting film portion 221 b as inthe case of the above-described ninth embodiment. In addition, thesolder balls 11 may be deposited only on the device-mounting filmportion. Further, the solder balls 11 may or may not be deposited onboth the external-connection film portions and the device-mounting filmportion. Moreover, the inner leads may be bonded directly to the chipelectrode pads as in the case of the above-described third embodiment.Additionally, insulating resin projections such as those of theabove-described 20th embodiment may be provided on a second surface ofthe device-mounting film portion 221 b.

FIG. 23 shows a cross-sectional structural diagram illustrating asemiconductor device in accordance with a 23rd embodiment of the presentinvention. Incidentally, in FIG. 23, those parts and portions which areidentical to those shown in FIGS. 1 to 22 are denoted by the samereference numerals.

The semiconductor device shown in FIG. 23 is comprised of a package film231 and an LSI chip 232 in which chip electrode pads 232 a are formed ina peripheral portion of the chip surface. The package film 231 iscomprised of a device-mounting film portion 231 b, anexternal-connection film portion 231 c, and a bending portion 231 dlocated therebetween.

First, the package film 231 is fabricated. Namely, in the same procedureas that of the above-described first embodiment, the inner leads 3 areformed by effecting patterning on the base resin 2 in which a devicehole 233 has been formed in its peripheral portion in correspondencewith the chip-electrode-pad forming region of the LSI chip 232 and abending hole has been formed. Then, the insulating resin 4 is formed byeffecting patterning thereon, thereby forming the external electrodepads 5. The external electrode pads 5 are formed also on the inner-leadforming surface of the device-mounting film portion 231 b. Although thedevice hole 233 is not a hole as such, but a notched portion provided inthe peripheral portion. However, since its function is identical to thatof the device hole 183 in accordance with the above-described 18thembodiment, it is referred to as the “hole.” Incidentally, the elasticresin 6 should preferably be coated to prevent the deterioration of thestrength of the inner leads 3 in the bending portion. The package film231 is fabricated in the above-described manner.

Next, in the same way as in the above-described 19th embodiment, the LSIchip 232 is mounted on the device-mounting film portion 231 b in a statein which the base resin surface of the device-mounting film portion 231b faces the surface of the LSI chip 232. Namely, the inner leads 3 arecollectively bonded by thermo-compression bonding to the chip electrodepads 232 a of the LSI chip 232 on which the bumps 7 have been formed.Then, the encapsulating resin 9 is allowed to flow into the space formedby the device-mounting film portion 231 b and the surface of the LSIchip 232, thereby fixing and mounting the LSI chip 232 on thedevice-mounting film portion 231 b.

Next, the external-connection film portion 231 c is bent 180° at thebending portion 231 d in such a manner as to be superposed on a reversesurface 232 b of the LSI chip 232, and is secured to the reverse surface232 b of the chip by means of the adhesive 10. Finally, the solder balls11 are deposited on the external electrode pads 5 on theexternal-connection film portion 231 c. Here, the solder balls 11 arenot deposited on the external electrode pads 5 of the device-mountingfilm portion 231 b.

As for the semiconductor device shown in FIG. 23, a plurality ofsemiconductor devices can also be laminated in the same way as in theabove-described 22nd embodiment. Accordingly, a plurality of thesemiconductor devices shown in FIG. 22 can be laminated and mounted on amother board.

Thus, in accordance with the 23rd embodiment, since the externalelectrode pads 5 are also provided on the device-mounting film portion231 b, and the external-connection film portion 231 c is fixed to thereverse surface of the LSI chip, it is possible to reduce the wiringlength, protect the reverse surface of the LSI chip, and flatten theexternal-connection film portion, and the laminated mounting on themother board (three-dimensional mounting) becomes possible. Hence, itbecomes possible to reduce the mounting space in the mother board.Further, since one external-connection film portion is used, it ispossible to improve the positional accuracy of the external electrodepads 5 as compared with the above-described 22nd embodiment.

It should be noted that the solder balls 11 may be deposited only on thedevice-mounting film portion 231 d. Further, the solder balls 11 may ormay not be deposited on both the external-connection film portion 231 cand the device-mounting film portion 231 b. Moreover, the inner leadsmay be bonded directly to the chip electrode pads as in the case of theabove-described third embodiment. In addition, a plurality ofexternal-connection film portions may be provided. Further, insulatingresin projections such as those of the above-described 20th embodimentmay be provided on the second surface of the device-mounting filmportion 231 b. Still further, it is possible to adopt a structure inwhich the external-connection film portion and the bending portion arenot provided as in the case of the above-described 18th or 19thembodiment.

It should be noted that the mounting of the semiconductor device on themother board is effected as described below. Referring to FIGS. 27A and27B, a description will be given by citing as an example thesemiconductor device in accordance with the first embodiment.

FIG. 27A shows a schematic cross-sectional view of a mother board 300 onwhich the semiconductor device in accordance with the first embodimentis mounted. First, prior to the mounting of the semiconductor device,the solder balls 11 are deposited on electrode pads 302 of the motherboard 300. Next, the semiconductor device is placed on the mother board300. At that time, the semiconductor device is placed in such a way thatthe electrode pads 302 of the mother board 300 correspond to theexternal electrode pads 5 of the semiconductor device. Finally, thesolder balls 11 are melted to electrically connect the mother board 300and the semiconductor device.

Since the solder balls 11 are deposited on the mother board 300, itbecomes possible to mount a plurality of packages simultaneously. Hence,there is an advantage in that the number of steps of mounting thesemiconductor devices on the mother board 300 can be reduced. Inaddition, since the step for depositing the solder balls 11 on theexternal electrode pads 302 becomes unnecessary in the process formanufacturing the semiconductor device, there is an advantage in thatthe number of processing steps can be reduced, and it is possible tofurther lower the cost of the packages.

Further, in the 22nd and 23rd embodiments, in the case where a pluralityof semiconductor devices are laminated and mounted on the mother board300, the procedure described below is taken. Referring to FIG. 28, adescription will be given by citing the semiconductor device of the 23rdembodiment as an example.

FIG. 28 shows a state in which two semiconductor devices are placed onthe mother board 300 in a superposed manner, and are electricallyconnected. To laminate such a plurality of semiconductor devices, first,the external electrode pads formed on either the external-connectionfilm portion or the device-mounting film portion of the firstsemiconductor device are superposed on the electrode pads 302 of themother board 300, and the external electrode pads formed on either theexternal-connection film portion or the device-mounting film portion ofthe second semiconductor device are superposed on the external electrodepads formed on another film portion of the first semiconductor device,such that the superposed electrodes are electrically connected. Itshould be noted that the electrical connection is established as thesolder balls 11 are deposited in advance on the mother board 300 and thesemiconductor devices between the superposed electrodes, and the solderballs 11 are then melted.

In accordance with the above-described method, an advantage can beobtained in that since a plurality of semiconductor devices arelaminated and mounted, the mounting space on the mother board can besaved.

1. A semiconductor device comprising: a semiconductor chip having a mainsurface, a back surface and a plurality of side surfaces; a plurality ofelectrodes arranged in a plurality of lines on the main surface of thesemiconductor chip: a base resin film formed on the main surface of thesemiconductor chip and having a plurality of electrode holes formedtherein, the base resin film having a first surface facing the mainsurface of the semiconductor chip, a second surface opposite to thefirst surface and a through hole provided thereof; a plurality ofconductive patterns formed on the first surface of the base resin film,the conductive patterns extending in the through hole; and an insulatingfilm formed on the first surface of the base resin film and theconductive patterns, wherein the conductive patterns extending in thethrough hole are connected with the electrodes, and the plurality ofelectrodes holes expose a part of the conductive patterns.
 2. Asemiconductor device according to claim 1, wherein the main surface andside surface of the semiconductor chip are covered by molding resin. 3.A semiconductor device according to claim 1, further comprising aplurality of solder balls formed on the electrode holes.
 4. Asemiconductor device according to claim 1, wherein the base resin filmis formed on the main surface, back surface and side surfaces of thesemiconductor chip.
 5. A semiconductor device according to claim 1,wherein the base resin film is covered by elastic resin.
 6. Asemiconductor device according to claim 5, wherein the elastic resin ispolyimide.
 7. A semiconductor device comprising: a semiconductor chiphaving a main surface, a back surface and a plurality of side surfaces;a plurality of electrodes arranged in a plurality of lines on the mainsurface of the semiconductor chip; a base resin film formed on the mainsurface of the semiconductor chip, the base resin film having a firstsurface facing said semiconductor chip, a second surface opposite to thefirst surface, a through hole and a plurality of electrode holesprovided thereof; a plurality of conductive patterns formed on the firstsurface of the base resin film, the conductive patterns extending in thethrough hole; an insulating film formed on the first surface of the baseresin film and conductive patterns, wherein the conductive patternsextending in the through hole are connected with the electrodes, and aplurality of electrode holes exposing a part of the conductive patterns.8. A semiconductor device according to claim 7, wherein the main surfaceand side surface of the semiconductor chip are covered by molding resin.9. A semiconductor device according to claim 7, further comprising aplurality of solder balls formed on the electrodes holes.
 10. Asemiconductor device according to claim 7, wherein the base resin filmis formed on the main surface, back surface and the side surfaces of thesemiconductor chip.
 11. A semiconductor device according to claim 7,wherein the base resin film is covered by elastic resin.
 12. Asemiconductor device according to claim 11, wherein the elastic resin ispolyimide.
 13. A semiconductor device comprising: a semiconductor chiphaving a main surface, a back surface and a plurality of side surfaces;a plurality of electrodes arranged in a plurality of lines on the mainsurface of the semiconductor chip; a base resin film formed on the mainsurface of the semiconductor chip, the base resin film having a firstsurface facing said semiconductor chip and a second surface opposite thefirst surface and having a plurality of second electrode holes; aplurality of electrode patterns formed on the first surface of the baseresin film; a first insulating film formed on the first surface of thebase resin film, the first insulating film having a plurality of firstelectrode holes for exposing the electrode patterns; a plurality ofconductive patterns formed on the second surface of the base resin film,the conductive patterns electrically connected to the electrodepatterns; and a second insulating film formed on the second surface ofthe base resin film and the conductive patterns, wherein the secondelectrode holes expose a part of the conductive patterns.
 14. Asemiconductor device according to claim 13, wherein the main surface andthe side surface of the semiconductor chip are covered by molding resin.15. A semiconductor device according to claim 13, further comprising aplurality of solder balls formed on the second electrodes holes.
 16. Asemiconductor device according to claim 13, wherein the base resin filmis formed on the main surface, back surface and the side surfaces of thesemiconductor chip.
 17. A semiconductor device according to claim 16,wherein the base resin film is substantially surrounding thesemiconductor chip.
 18. A semiconductor device according to claim 13,wherein the base resin is covered by elastic resin.
 19. A semiconductordevice according to claim 18, wherein the elastic resin is polyimide.